U.S. Pat. No. 4,469,553 discloses an apparatus for the assembly, testing, and repair of circuit boards. This apparatus has a work surface for accommodating and retaining a circuit board, which is to be assembled. The circuit board is fixed to this holding surface by means of suction elements. A half-silvered mirror is positioned just above the work surface, and above the half-silvered mirror is an image projector. The image projector is used to project images of the components to be inserted and the track data on to the mirror. A user of the apparatus, looking through the half-silvered mirror, sees the image projected on to the half-silvered mirror by the projection equipment, together with the circuit board positioned behind. The user thus has the impression that this projected image is projected onto the circuit board, thereby marking the locations to be equipped with a relevant circuit component.
U.S. Pat. No. 5,513,099 describes an apparatus for the repair and processing of circuit boards. This apparatus has a work surface on which a circuit board to be examined may be fixed. A camera is mounted above the work surface, on a slide mechanism, which may be moved in a horizontal plane. The camera is capable of being located automatically over any desired point of the circuit board, which is to be examined. This apparatus has a computer with a video screen, a keyboard and a computer mouse.
Using this apparatus, a circuit board to be examined is fixed on the work surface. A digital image of the circuit board is then generated by the camera and displayed on the screen. The so-called “GERBER” data are superimposed on this image. The operator may then enter defect information, causing the camera to be positioned automatically over the section of the circuit board to which the defect information relates. The operator may then enlarge the camera image together with the image of the “GERBER” data. In this way the operator may observe and analyze the relevant area using an enlarged view.